---
sourceDocument: Australia Telecommunications Network Inventory
sourceDocumentLink: https://www.servicenow.com/docs/r/australia/telecom-network-inventory

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia Telecommunications Network Inventory

ft:clusterId :

    - telninv

bundleId :

    - telninv

workflow :

    - Customer and Industry


---

# Name pattern validation

# Name pattern validation {#ariaid-title1}

Release version: Australia  
Updated November 5, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 2 minutes to read
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## Summary of Name pattern validation

Name pattern validation in ServiceNow runs twice to ensure accuracy and consistency in inventory template hierarchies.
It performs validation both when saving a pattern and when loading the Overview tab of the inventory template hierarchy.
This dual validation approach helps prevent errors and identifies issues related to template relationships, such as duplicate names among sibling templates.
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## Save-time validation

When creating or editing a name pattern in the Define name pattern modal, the system validates the pattern before allowing it to be applied. This validation checks that the pattern is a valid expression producing a non-empty string. Feedback is provided immediately:

* **Valid pattern:** A green message appears confirming "Valid name pattern" with a sample resolved name shown, and the Apply button is enabled.
* **Invalid pattern:** A red error message indicates issues such as empty results, invalid JavaScript, or undefined variables, and the Apply button is disabled.

The pattern is only saved to the record after applying a valid pattern and saving the record itself. Closing the modal or record without saving discards changes.

## Hierarchy render validation

When the Inventory Template Overview tab loads, it evaluates the hierarchy and runs registered validation providers against the resolved names of related templates at each tree level. The default validation checks for duplicate names among siblings under the same parent, flagging any conflicts.

Validation providers operate per sibling group and record results for any related templates that fail rules. Multiple validation rules can apply to a single template, and their messages are combined in the Overview tab's Validation failed banner, though the tree node error badge displays only one label (set by the last provider).

You can extend or replace the default duplicate-name check by registering custom validation providers to fit specific requirements.

## Handling unresolvable variables in patterns

Name patterns that reference variables not applicable in a template's context (for example, a variable for a parent slot name when no parent exists) result in the system substituting a question mark (?) in the resolved name displayed on the tree node label. This substitution serves as a visual indicator of variable mismatches but does not trigger error badges or validation failure banners.  
Name pattern validation runs twice. It runs at save time to prevent errors. And it runs when the Overview tab loads the hierarchy to catch issues specific to template relationships.

Save-time validation
:   Evaluates whether the pattern is a valid expression that produces a non-empty string.

Hierarchy render validation
:   Evaluates cross-template rules registered as validation providers --- for example, duplicate names among siblings.

## Save-time validation {#naming-pattern-validation__save-time-validation}

When you create or edit a pattern in the Define name pattern modal, the modal validates the pattern before you can apply it. Two outcomes are visible in the modal:

* Pattern accepted: A green message appears beneath the input: Valid name pattern. Preview: \<resolved name\>. The resolved name in the preview is a sample evaluation. The Apply button is enabled.
* Pattern invalid or produces an empty result: A red message appears: Name pattern results in empty name. Please try again. The Apply action is blocked. The same message appears if the pattern has invalid JavaScript, references a variable that does not exist, or produces an empty string when evaluated.

{#naming-pattern-validation__ul_x1b_x3d_xjc}

The pattern is committed to the record only when you select Apply on a valid pattern and then save the underlying record. If you close the modal or close the record without saving, the pattern is not
persisted.

## Hierarchy render validation {#naming-pattern-validation__overview-render-validation}

When the Inventory Template Overview tab evaluates the hierarchy, registered validation providers run against the resolved names of related templates. Each provider evaluates siblings under a single parent at
one tree level at a time and records validation results for any related template that fails its rule.

The application includes a default duplicate-name check that flags two or more siblings whose patterns resolve to the same name. For example, if two slots at the same level both resolve to `Slot -5`, both slots are
flagged. The check is scoped to direct siblings of the same parent and does not compare names across different branches.

You can extend or replace this default check by registering additional validation providers. For more information, see [Extension point for custom name validation](https://www.servicenow.com/docs/s4l5gViXtJg0QWdr8s9Utw "The custom name validation extension point validates resolved names in the Inventory Template Overview tab. Administrators can register custom validation rules to enforce organization-specific naming conventions, replacing or extending the default check.").

## Multiple validation rules {#naming-pattern-validation__multiple-validation-rules}

When multiple validation rules flag the same related template, the Overview tab combines their outputs:

* The Validation failed banner concatenates the error descriptions from all providers that flagged the related template, separated by `; ` (semicolon and space). All errors are visible in one banner.
* The Error badge on the tree shows only one label. When multiple providers each write a badge label, the badge displayed on the node is set by the last provider to flag the related template.

The following banner shows output when a related template fails both a custom check and the default duplicate-name check.

    Validation failed: Slot name exceeds maximum length: Slot -4; Duplicate name at same level: Slot -4

## Unresolvable variables in resolved names {#naming-pattern-validation__unresolvable-variables}

Patterns can reference variables that have no value in a particular related template's context. For example, a top-level slot directly under an equipment template has no parent slot, so the variable
`parent_slot_name` can't be resolved for it.

When the Inventory Template Overview detects an unresolvable variable, it substitutes `?` for the variable in the resolved name on the tree node label . The `?` substitution
is a signal that the pattern is using variables that do not fit the related template's position in the hierarchy.  
Note:  
The `?` substitution does not raise an Error badge or a Validation failed banner. It is a display-only indicator in the tree node label.
**Related concepts**   

* [Inventory template hierarchy view](https://www.servicenow.com/docs/OS5FfXQqJRLARW~lpc5gSw "The Overview tab on an inventory template record shows the full template hierarchy as a tree. Use it to check resolved CI names and spot validation errors before deploying the template.")
* [Extension point for custom name validation](https://www.servicenow.com/docs/s4l5gViXtJg0QWdr8s9Utw "The custom name validation extension point validates resolved names in the Inventory Template Overview tab. Administrators can register custom validation rules to enforce organization-specific naming conventions, replacing or extending the default check.")
* [Inventory template naming patterns](https://www.servicenow.com/docs/Ur7JKaJYvarOaFuXVjwhTg "A naming pattern is a JavaScript expression that defines how a configuration item (CI) is named when it is created from an inventory template.")